JPH0351520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to small press dies, for example, for driving pressurizing or cutting dies for crimping lead wires of crimp terminals, cutting wires, electric wires, etc., or crimping rivets. The present invention relates to a control device for a small press device.

BACKGROUND TECHNOLOGY Conventionally, a handy and powerful power device has not been seen as a small pressure or cutting press, and press devices and rivet riveting devices are generally large and stationary.

These devices operate by rotating the motor in forward and reverse directions for each cycle, or operate a micro switch or the like when the device completes forward rotation to cause the motor to rotate in the opposite direction. There is one that controls the point range over time, switches to reverse, raises the ram, and completes one cycle. In addition, there are also those that stop one cycle using a clutch, etc., and those that operate continuously for one cycle without using any control, but are stopped by judging the work situation and turning off the power switch. be.

Problems to be Solved by the Invention However, there is a problem in that the precision of the devices using microswitches and the method of controlling the time of one cycle inevitably decreases (direct position accuracy due to inertial force is low). (regulated). moreover,
Although it has a function to prevent damage to the motor due to overload, there is no protection function against malfunction due to power supply abnormality. Moreover, it is extremely inconvenient if the device does not have a single cycle stop function and only operates continuously.

This invention has been made to solve the above-mentioned problems, and aims to provide a compact, lightweight, and safe press device powered by an extremely small electric motor.

Measures to Solve the Problem Therefore, we used a small electric motor as the power source and used a speed reducer to obtain appropriate rotational force to cause the cam to rotate eccentrically.On the other hand, a swing lever was attached to the fulcrum shaft provided on the fixed lever. A power transmission section formed at the rear end of the swinging lever is brought into sliding contact with the cam to convert the rotation of the cam into a swinging motion of the swinging lever, and the fixed lever and the swinging lever are Position detection for detecting the end of one stroke of the cam in a small press device that opens and closes a pressurizing or cutting die that is axially connected between the tip parts and performs pressurizing, cutting, etc. in the narrow pressure part. an overcurrent detector that detects an abnormal load, etc. after delaying the detection operation by the inrush current passage time when the power switch of the motor is turned on; and an overcurrent detector that detects an abnormal load, etc. a time detector for detecting when a predetermined time or more has elapsed; means for disconnecting the power supply circuit of the electric motor based on signals from the three detectors; and means for detecting that one stroke of the cam has been completed. A first feature of the control device for a small press machine is that the control device is provided with a means for detecting the power supply circuit of the electric motor, and short-circuiting the terminals of the electric motor to immediately stop the electric motor. Further, in the control device, a recess is provided on a side surface of the power gear in which the cam is formed;
The second feature is that the electric switch configured to operate the push rod is used as a position detector, and the position detector is an electric switch that is turned on and off by eccentric movement of the cam. By making this the third feature, the above-mentioned problem is solved.

Function: Since the movement of the cam formed on the side of the moving gear is detected by a position detector, one cycle controllability is good. Moreover, the configuration is such that the power supply circuit is cut off and the motor is immediately stopped by controlling the position detector, overcurrent detector, and time detector, so that safety is extremely high. Furthermore, even if the power supply voltage drops and the operating time becomes abnormally long, the time detector can detect this and stop the operation.

Embodiment An embodiment of the present invention will be described below based on the drawings. In the figure, 1 is an electric motor, the output shaft of which is connected to a reducer 2, and a pinion 3 is connected to the reducer 2.
Rotate. The pinion 3 is meshed and connected to the power gear 4, and the rotational force of the electric motor 1 is reduced by a reduction gear 2 at an appropriate reduction ratio and transmitted to the power gear 4 via the pinion 3. The power gear 4 is provided with an eccentric cylindrical cam 4' on the side opposite to the electric motor, and the cylindrical cam 4' rotates eccentrically in accordance with the rotation of the electric motor. A sliding ring 6 is rotatably fitted on the outer periphery of the eccentric cylindrical cam 4' via a bearing member 5. 7 is a sliding plate that reciprocates from the bottom dead center to the top dead center according to the eccentric rotation of the sliding ring 6 fitted to the eccentric cylindrical cam 4';
The sliding plate is formed in an inverted L-shape, the upper horizontal plate-like part contacts the sliding ring 6, and the central part of the hanging plate-like part has a vertically elongated through hole into which the rotating shaft of the power gear is loosely fitted. , both side parts are fitted into sliding guides provided in the motor case 8, inserted between the bearing part of the power gear 4 and the end face of the eccentric cylindrical cam 4', and the lower face of the horizontal plate part and the sliding ring 6 are inserted. The contact position of the cam is configured to reciprocate in the vertical direction while always maintaining a horizontal state even if it moves left and right according to the eccentric rotation of the cam.

Further, a fixed lever 9 fixed to the front end of the electric motor case 8 is provided with a fulcrum shaft 11 in a direction perpendicular to the axis of the power gear 4, and a swing lever 1 is provided on the fulcrum shaft 11.
0 is axially connected. A contact roll 12 is axially coupled to a power transmission portion formed at the rear end of the swing lever, and this contact roll 12 connects to the sliding plate 7 described above.
is in contact with the top surface of the Therefore, when the sliding plate rises due to the eccentric rotation of the cam 4', the power transmission section of the swing lever 10 is correspondingly pushed up via the contact roll 12 about the fulcrum shaft 11.
At this time, the contact roll 12 rotates and moves rearward by the amount of parallel displacement of the contact roll mounting portion due to the rotation of the swing lever about the fulcrum shaft 11.

A pressurizing or cutting die 14 is coupled via a shaft 13 between the tips of the fixed lever 9 and the swinging lever 10, and the narrow pressure portion of the die 14 is cut by the swinging movement of the swinging lever. They operate so as to engage under pressure around the shaft 15.

Note that 16 is a die holding plate for holding the upper and lower die bodies by the shaft 15. 17 is electric motor 1
18 is a relay. The relay includes a power switch that opens and closes a circuit that supplies power from a power source 17 to the motor 1, and a means for disconnecting the power circuit of the motor in response to a signal from a position detector, a time detector, or an overcurrent detector, which will be described later. and a means for detecting the completion of one stroke of the cam, disconnecting the power supply circuit of the motor, and short-circuiting the terminals of the motor to immediately stop the motor. A position detector 19 detects one rotation of the eccentric cylindrical cam 4'. 20
21 is a time detector consisting of a timer or the like that detects when the elapsed time of one stroke of the eccentric cylindrical cam 4' has exceeded a predetermined time;
In order to prevent the torque of the motor 1 from increasing due to the application of an abnormal pressurizing reaction force to the motor 1, an excessive current flows to the motor 1 and causes damage, it is detected that the current exceeds a predetermined value. It is an overcurrent detector. Furthermore, 22 is a delay circuit that stops the overcurrent detector 21 for a period of time during which the inrush current passes, in order to prevent the overcurrent detector from operating due to the inrush current immediately after the power switch of the motor is turned on.

In the above device, when the power switch of the relay 18 is turned on, the electric motor starts rotating. This rotational force is transmitted to the cam, causing the cam to perform eccentric rotational motion.
The eccentric rotational motion of the cam is converted into linear reciprocating motion by the sliding plate, and this linear reciprocating motion of the sliding plate is transmitted to the swinging lever to cause the swinging lever to swing. Due to this swinging movement, the narrow pressure portion of the pressurizing or cutting die that is axially connected to the tip of the swinging lever and the corresponding fixed lever operates so as to press into engagement with each other.

In the device of the present invention, when an abnormal reaction force is generated in the die section etc. by accidentally compressing an article exceeding the rated capacity, and the motor is overloaded, an overcurrent will flow and damage the motor etc. In order to prevent this, when the load current exceeds a predetermined value, the overcurrent detector 21 detects this and transmits the signal to the relay, thereby cutting off the relay power supply circuit. When the motor is started, an excessive starting current that reaches several times the rated current flows due to static inertia, but the overcurrent detector 21 catches this starting current and transmits the signal to the relay. In order to prevent the relay from cutting off the power supply circuit and stopping its operation, the overcurrent detector 21 is provided with a delay circuit 22 to avoid overcurrent detection for a predetermined period of time required when the starting current flows in, and then, It is configured to operate the overcurrent detector 21. Additionally, if there is an abnormality in the power supply that supplies power to the motor and a power shortage occurs, the motor's rotational speed and torque will generally decrease, but in this case, the necessary operating force cannot be transmitted to the pressurizing or shearing die. Phenomena such as fatigue or abnormally long operating time may occur. To avoid this phenomenon, we use a timer, etc. that starts operating at the same time as the power switch is turned on to operate the motor, and detects when the motor's rotation time exceeds the predetermined rotation time and sends that signal to the relay. By transmitting, the relay has a time detector to interrupt the power circuit. Furthermore, in this device, the operation of the pressurizing or shearing die must be stopped when one stroke is completed. When the cam rotates once from the electromotive force of the electric motor via the reducer, pinion, and power gear, the swinging lever swings once, causing the die part to move once. In order to detect the end of this one stroke, a position detector consisting of an electric switch is formed with a concave part 24 on the side opposite to the cam of the power gear, that is, on the side on the electric motor side, and a push rod 25 is brought into contact with this concave part 24. 19 is activated to generate a one-stroke end signal, and this signal is transmitted to the relay, which causes the relay to cut off the power supply circuit. Note that this position detector can also be arranged in the bottom dead center region of the cam, etc., and operated by utilizing the eccentric rotational movement of the cam formed in the power gear.

Furthermore, in preparation for the next operation, this device
After the stroke is completed, it is desirable that the maximum eccentric position of the cam stops at a position opposite to the swing lever. For this reason, in the device shown in the embodiment, the position detector 19 operates, the relay cuts off the power supply circuit, and at the same time short-circuits the terminals of the motor 1, so that the motor is electrically controlled.

Effects As described above, in the device of the present invention, the motor current is cut off using the position detector that detects the completion of one stroke, and the motor current is cut off when the device is overloaded or due to a drop in the power supply voltage, etc. If the number or torque decreases and the operating time for one stroke becomes abnormally long, the delay circuit and overcurrent detection circuit or time detector will stop the operation and prevent damage to the motor or change in the moving parts of the equipment. Furthermore, when one stroke is completed, the motor current is cut off, and at the same time, the terminals of the motor are short-circuited to activate electrical control and stop the operation immediately, which is extremely effective in protecting equipment and improving work efficiency. be.

[Brief explanation of drawings]

The figure is a sectional view showing one embodiment of the present invention. 1...Electric motor, 4...Power gear, 4'...Cam,
9... fixed lever, 10... rocking lever, 14...
...Dice, 17...Power supply, 18...Relay, 19
...Position detector, 20...Time detector, 21...
Overcurrent detector, 22...delay circuit.

Claims (1)

[Scope of Claims] 1. A swinging lever is axially coupled to a fulcrum shaft of a fixed lever, and the swinging lever is configured to swing by a cam formed on a side surface of a gear driven by an electric motor, A small press device in which a pressurizing or cutting die is axially coupled to the tips of the swing lever and the corresponding fixed lever, comprising: a position detector for detecting the end of one stroke of the cam; and a power source for the electric motor. An overcurrent detector that detects an abnormal load, etc. after delaying the detection operation by the inrush current passage time when the switch is turned on, and when the time required for one stroke of the cam after the power switch of the motor is turned on has elapsed for a predetermined time or more. a time detector for detecting this; a means for disconnecting the power supply circuit of the motor based on signals from the three detectors; and means for detecting that one stroke of the cam is completed and disconnecting the power supply circuit of the motor. 1. A control device for a small press machine, comprising: a means for disconnecting the motor and immediately stopping the motor by short-circuiting the terminals of the motor. 2. A small press according to claim 1, characterized in that a recess is provided in the side surface of a power gear in which a cam is formed, and an electric switch configured to operate a push rod is used as a position detector. Device control device. 3. The control device for a small press machine according to claim 1, wherein the position detector is an electric switch that is turned on and off by eccentric movement of the cam.